Diabetes mellitus is a metabolic disorder characterized by hyperglycemia, insulin resistance, and is often associated with other disorders such as obesity, hypertension, hyperlipidemia, as well as complications such as cardiovascular disease, retinopathy, neuropathy, and nephropathy. The disease is progressive in nature, and can often be controlled initially by diet alone, but generally requires treatment with drugs such as sulfonylureas and injections of exogenous insulin. A new class of compounds known as the glitazones has recently received a great deal of attention for their ability to treat diabetes. These compounds operate by increasing the sensitivity of insulin receptors throughout the body, thereby diminishing or eliminating the need for exogenous insulin. Another agent known as a biguanide also is used to decrease hepatic glucose production as well as intestinal absorption of glucose.
It has now been discovered that combination therapy with a biguanide and a glitazone results in dramatic improvement in glycemic control, and that even better control can be achieved by using a combination comprised of a biguanide, a glitazone, and a sulfonylurea. Accordingly, such combinations are especially useful in treating diabetes and associated complications.